Clutch control mechanism



Patented Nov. 15, 1,938

UNITED STATES PATENT OFFICE CLUTCH CONTROL MECHANISM Henry J. De N. McCollum, Evanston, lll.

Application October l1, 1935, Serial No. 44,522

' 14 claims. v (o1. isz-.01)

This invention relates to power means for operating the clutch of an automotive vehicle.

The development of this art has, in large measures, been based upon a type of accelerator controlled vacuum clutch actuator in which the clutch is automatically disengaged whenever the accelerator is released, thus causing unnecessary wear of the clutch throw-out bearing and also effecting a free-wheeling action of the vehicle.v l0 This latter action would be particularly objectionable when it is v,desired to employ the engine as a brake, the transmission at that time usually being in high gear. Y

The present invention is therefore directed to l5 means for cutting out of operation the clutch operating power means, when and if the transmission is in high gear and the engine is not being employed as a brake. I

A further object of the invention is to pro- 20 vide, in an accelerator controlled vacuum clutch operator, a power operated cut-out valve controlled in part by a gear shift lever operated three-way valve.

Yet another object of the invention is to pr 25 vide a manifold vacuum operated cut-out valve for a clutch operator, said valve being operable as such. when and if the manifold vacuum is maintained at orabove amredetermined factor.

Yet another object is to provide, in a mani- 30 fold vacuum operated automatic clutch mechanism, means for cutting out of operation said mechanism when the gear shift lever is moved to its high gear position and the degree of intake manifold vacuum is above that normally effected by an idling engine;l

Other objects of the invention and desirable details of construction and combinations of parts will becomeap'parent from a detailed description of certain embodiments of-'the invention,

40 described in detailA in the following specification taken in conjunction with the accompanying drawing illustrating said embodiments, in which: Figure 1 is a diagrammatic view of the clutch control mechanism constituting my invention;

445 Figure 2 is a sectional view of the cut-ofi valve `unit of the mechanism of Figure 1;

Figure 3 is a sectional view of a modified form of cut-oi! valve unit; and

Figure 4 is a sectional view of theA clutch servo 5o motor and attached control valve unit of the mechanism of Figure l..

Referring to Figure 1, disclosing a preferred embodiment.` of my invention, a conventional clutch pedal l0 connected to a conventional disc 55 clutch generally indicated at I2 is in part operatively connected to a piston I4 of a manifold vacuum operated pressure differential servo motor I6 by a connecting rod I8. The servo motor I6 is placed.` in fluid `transmitting Aconnectionywith an intake manifold 20 by a conduit 22, a com- 5 bined three-way and cut-out valvular unit 24 being incorporated in said conduit. A transmission and manifold vacuum controlled power operated cut-out valve unit 26, constituting the essence of my invention, is also incorporated in 10 said conduit.

The clutch servo motor I6 and control valve unit 24, disclosed in detail in Figure 4, constitute no part of my invention, the same being that of Victor W. Kliesrath, disclosed, described and claimed in his application No. 721,683, led April 21, 1934.

Referring to the operation of said mechanism for a more detailed vdescription thereof; upon release of an accelerator 28, operatively connected to a throttle 3U by a link 32 and to a combined three-way and bleed valve plunger 34 of the valve unit 24 by a link 36, the manifold 20 is placed in communication with the vacuum corr oartment 38 of the servo motor I6 via the conduit 22 and 25 waist portions and 42 of plunger 34 and a cutout valve plunger 44 respectively. The cut-out o valve is operable by a Bowden control 46. The compartment 38 is thereupon evacuated toeffect a movement of the piston I4 to the clutch disenso gaged position shown in Figure 4.

To reengage the clutch the operator depresses the accelerator 28 to first move the valve plunger 34 to the left, Figure 4, to first cut olf communication between the compartment 38` and the 35 manifold and then vent said compartment to the atmosphere via a slot 48 inthe plunger. The engagement of the clutch'under the action of its springs is thus initiated, said engagement being controlled by controlling the egress of air 40 froml the high pressure compartment of the clutch servo motor. The air ilrst rushes from said latter compartment relatively rapidly, to e'ffect a rapid movement of the clutch pedal, via the conduit in' hollow piston rod I which is con- 46 trolled by a. valve mechanism 52, said mechanism being `.more completely described, Vdisclosed and cainieei in an application of Caleb S. Bragg, Serial No. 643,499, filed November 19, 1932.

By way of brief description for purposes of 50 this case it may be statedthatthe hollow piston `rod I set in piston I4 has a port2, connecting 2 poppet valve 52 which is normally held against the open end of said hollow piston rod by a compression spring 5, anchored in the outer end of said sleeve, thus serving to close all exit for air from said piston rod interior so long as said spring is expanded. The stem I8 of said valve projects beyond the outer end of sleeve 3 and is provided with a clevls 8 for connection to any clutch pedal such as that indicated at I6 in Fig. 1. The sleeve 3 has an outlet port 1 in its wall near the end to which the hollow piston rod I is connected. The clutch generally and diagrammatically indicated at I2 in Fig. 1 is of any conventional construction, the clutch lever I6 being pivoted at 8, and composed of the usual two revoluble plates indicated at I3 and 4, normally forced together by a spring indicated at I5. One plate, as I3 is as usual fast on the shaft of the car engine (not shown) while the other (4) revolves with the transmission shaft (also not shown), all in the manner well known in the automotive art. Plate 4 is pulled away from I3 by link 9 when pedal on lever III is depressed.`

II is a flexible boot on piston rod I.

When the clutch plates just contact. the valve 52 automatically closes and the remainder of the clutch engagement is controlled by a bleed valve mechanism comprising a tapered' slot 54 in the plunger 34, the air being led to said slot via a conduit 56. An inertia operated cut-off valve mechanism indicated generally at 58, the same having the-construction shown in application Serial No. 622,513, filed July 141932 by Harold W. Price, is incorporated in said bleed conduit to automatically and momentarily stop the bleed of air from the compartment 56, should the acceleration of the vehicle exceed a predetermined maximum.

This inertia-actuated valve mechanism indicated generally by 56 is of the type also shown and broadly claimed in my copending application Ser. No. 645,676, filed December 3, 1932, passage through the conduit beingcontrolled by sliding piston valve I1 which is shut when pendulum I9 swings backward (toward the right) as the car is suddenly started into movement (as by sudden closing of clutch I2 while the engine is running fast), or is similarly sharply accelerated (as in stepping up gearing). 2| is fastene'dto the lower end of the pendulum prevents it swinging forward and closing conduit 58 when the forward motion of the car is checked.

Operation of the described system of automatic valves shown may be briefly outlined as follows: Spring 5 presses on valve 52 with less force than that exerted by the pull of clutch lever I6 von valve stem Il. Consequently, when piston I4 is retracted by vacuum action ports 2 and 1 are connected, and ^as the clutch lever pulls piston I4 to the right when the vacuum behind the latter is reduced the air in space 5l is pushed out through the hollow piston I., issuing as a Jet through port 1. When, however, the clutch plates I3 and 4 make contact the movement of valve 52 is retarded, and also that of piston I4, so that the resistance to motion of the piston presented by air trapped in space 53 and flowing out through port 1 is gradually reduced as the speed of the isuing jet is reduced', so that spring 5 can expand and pull the end of hollow piston rod I. against valve 52. Thereafter the air must escape through accelerator-controlled valvular unit 24 and inertia controlled valve 53, which severally operate as previously explained.

The mechanism of Figure 4 thus functions, upon release of the accelerator, to disengage the clutch, and upon depression thereof to effect a controlled two-stage engagement thereof, the clutch being automatically slipped by the inertia or pendulum operated valve 58, should the engagement be so severe as to jerk the vehicle.

My invention is directed to means supplementing the above-described clutch control invention, the object of the invention being to provide a cut-out valve operable to render the clutch control mechanism inoperative, when and. if the transmission is in high gear and the vehicle is overrunning the engine.

To this end there is provided a power operated 4cut-out valve mechanism, disclosed in detail in Figure 2. Said mechanism comprises a hollow cylindrical -casing 66 closed at one end by a plug 62 and at its other end by a tubular three-way `valve casing 64. A spool-shaped valve plunger ment 16 above the said valve plunger member 66 with the manifold 20 via ports 18 and 80, or connect'ing said compartment with the atmosphere via ports 18 and 82. Vents 64 and 86 in the plug 62 and casingl 64 respectively permit unrestricted movement of the plungers 66 and 14.

Valve plunger 14 is held in a position to interconnect the manifold and compartment 16 by the gear shift lever of the vehicle, shown in cross section at 88 in Fig. 1, the latter being selectively movable Within thev conventional H-shaped slot 96 of the transmission mechanism. When the shift lever is in its high gear position, as disclosed in Figure l, the member 8l contacts a link 92 secured to the plunger 14,' moving the latter to the above-described position, shown in solid `lines in-Figure 2. The stop In all other positions of the gear shift lever, that is when the same is in its low, second or reverse gear positions or in neutral, a valve spring 94 within the casing 64 functions to move the plunger 14 to the right of the position disclosed in Figure 2 to vent the compartment 16 to atnication between ports 1l and 12, that is communicatlon between the manifold and the clutch motor and thus prevent a power operationof .the clutch. This operation is effected by virtue of the difference in gaseous pressur acting upon the ends of plunger 66, the pressure of the atmosvrphere acting on the lower end Ill thereof and the gaseous pressure of the manifold acting upon its upper end II2. The two ends III and |52 thus constitute means operated by power to oper'ate the cut-oil' valve constituted by the central portion of the plunger.

clutch pedal.

It is also to be noted that the parts are so constructed and propor- "tioned that the cut-off valve closes before the compartment 38 of the clutch motor is sufficiently evacuated to impart any movement to the It follows from the above that the clutch remains engaged, when the transmission is in high gear, thus utilizing the engine as a brake and obviating unnecessary Wear on the clutch throwout bearing.

when thespeed of the vehicle is appreclably reduced, thereby obviating stalling of the engine. To this end the spring68 is so proportioned with reference to the length of compartment 16 in which it is to be located as to automatically lmove the plunger 66 downwardly, when and if the manifold vacuum is decreased to or below a predetermined factor. Y

When the vehicle is overrunning the engine. the latter then actingfas a brake, the manifold vacuum developed is considerably higher than that developed solely4 by an idling engine. Accordingly, when the engine .is no longer acting as a brake, that is when the speed of the vehicle is appreciably reduced and the manifold vacuum has been reduced to a'predetermined minimum,

the cut-off valve is automatically operable to reconnect the manifold with the clutch motor to disengage the clutch.

There is disclosed in Figure 3 a modified form of cut-ofi' valve mechanism similar in kall respects to that of Figure 2, with the exception of the provision of two compartments |04 and |06 interconnected yby a port |06 in a dividing wall I I0. A conduit I I2 leading to the clutch controlling power unit is Aconnected with compartment |04 and a conduit Ill` leading to the manifold is connected to the4 compartment |06. With such a construction thelower portion I I6 of the valve is, when in its raised, vacuum cutting oil' position, subjected to the low'gaseous pressure of the manifold upon an annular area of its surface concentric with its axis. The tendency of the plunger to cock or bind', as with the plunger 66 of -Fig` ure 2, is thus obviated. Furthermore, the absence of any excess of air pressure on any one side of the valve shown in Fig. 3 as it moves toward or from closed position, such as is present in the modification shown in Fig. 2, eliminates nearly all friction and consequent wear of the surfaces of valve and casing such as occur when lthe latter form is used. Such uneven wear would in time distort the cross sections of both valve and casing in Fig. 2 from their originally true circular outline and so destroy the initial close fit of the valve in its casingwhich must be preserved if leakage is to be prevented.

Also, thevalve in Fig. 3, while closing, moves in the direction of the current of air lflowing around it from chamber |06 through opening |08 to the -intake manifold. Such `rapid air current would (particularly during the latter half of the valves closing movement) exert considerable skin friction on the peripheral surfaces of the valveand impinge sharply on the lower sldeof its upper head, and as the drag so produced would be the direction of said closing movement it would accelerate and facilitate it.

`'Ihese advantages developed by the modification shown in Fig. 3 are similar to many inherent in an ordinary poppet valve construction (though it is not strictly of that type) and sharply distinguish both froman ordinary slide `valve of It is desirable, however, to auto- Ymatically disengage' the clutch piston or other form (such as shown in Fig. 2) in which unbalanced pressures andrapid `current; flow create side thrusts on the valve body, with the result that the consequent increased frictional drag ofthe valve against its casing tends to retard its closed motion-, as well as to result in leakage produced by wear'of theV parts, as hereinbefore explained.

There is thus provided a simple and effective, power operated cut-off valve` for an automatic clutch control mechanism, said mechanism being rendered inoperative by said valve only when and if the transmission is in high gear and the vehicle is overrunning the engine sufiiciently to create a manifold vacuum higher than that of an idling engine.

Although this invention has been described in connection with certain specific embodiments, the principles involved are susceptible of numerous other applications that will readily occur to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended'claims.

I claim:

1. In a clutch operating mechanism including an accelerator controlled pressure differential` trolled in part by the transmission voperating` mechanism ofthe vehicle.

2. In aclutch operating mechanism including an' accelerator controlled pressure differential operated motor operably connected with the clutch, ,a cut-out valve for said mechanism, and power means for operating said valve, said power means including vacuum operated means controlled in part by the transmission operating mechanism of the vehicle and in part by a spring of predetermined tension.

3. In a clutch operating mechanism including an. accelerator-controlled pressure differential operated motor operably connected with the clutch, a fluid pressure power operated cut-out valve for said mechanism, and means for con'- trolling said valve including the gear 'shift lever of the transmission.

4. In a clutch operating mechanism including lan accelerator controlled pressure differentialv operated motor operably` connected with the clutch, a cut-out valve for said mechanism, and means to operate said valve including pressure differential operated means, and means to control said latter means including a gear shift lever operated three-way valve.

5. In an automotive vehicle provided with a clutch, an engine having an intake manifold, and a transmission, power means for operating the i clutch comprising 'a pressure differential operated motor, and valve means for controlling said motor including a cut-out valve operated by said transmission and manifold vacuum.

6. In an automotive vehicle provided with a clutch,` an engine having an intake manifold and a transmission, power means for operating the clutchcomprislng a pressure differential operated motor, and valve means for controlling said motor including a power operated cut-off valve clutch comprising a pressure differential operated motor, and valve means for controlling said motor including a pressure differential operated cut-out valve and transmission operated means for controlling said valve.

8. In an automotive vehicle provided with a clutch, an Vvintake manifold and a transmission operating gear shift lever, power means for operating said clutch, and means for cutting out of operation said power means, said cut-out means including a power operated valve controlled in part by said shift lever and in part by the degree of vacuum within said manifold.

9. In an automotive vehicle provided with a clutch and an intake manifold, power means for operating said clutch comprising a pressure differential operated motor operably connected with the clutch, a fluid transmitting connection interconnecting said manifold and motor, a motor controlling three-way valve interposed in said connection, and a .manifold vacuum response power operated cut-out valve also interposed inv said connection between said manifold and three- Way Valve.

l manifold of a motor car, the combination, with y 10. 4In an automatic clutch-actuating apparatus comprising a vacuum-actuated servo-motor, and a conduit for connecting it to the intake said elements, of a valve controlling passage through said conduit adapted to be closed by the suction from said manifold, and means adapted to effect an opening of said valve only when the speed changing gears of -a car in which said apparatus is installed are in a position of low, or intermediate, speed adjustment;'whereby, when said gears are in high speed adjustment, said conduit valve is closed and said servomotor is cut ofl.' from connectionlwith said manifold, being thereby temporarily rendered inoperative, and said clutch actuating apparatus is cutout of action.

11. A vacuum actuated apparatus for opening and closing a friction clutch comprising a servomotor which is adapted to be operatively connected to the movable member of such a clutch and has a.vacuum space in its interior with a' conduit extending therefrom adapted to be connected to a vacuum creating device, combined open said connection independently o'f such vacu uum condition.

12. In an automatic clutch-actuating apparatus comprising a vacuum-actuated servo-motor, and a conduit for connecting it to the intake manifold of a motor car, the combination, with said elements, of a valve adapted to completely close all connection between said servo-motor vacuum space and said intake manifold so arranged that any suction existing in the latter tends to hold the valve in such closed position, and means adapted to effect anv opening of said valve only when the speed changing gears of a car in which said apparatus is installed are in a position of low, or intermediate, speed adjustment; whereby, when saidgears are in high speed adjustment, said conduit valve is closed and said servo-motor is cut off from connection with said manifold, being thereby temporarily rendered inoperative. and said clutch actuating apparatus is cut out of action.

13. A vacuum-actuated apparatusfor opening' and closing a friction clutch comprising a servo-v ually controllable means for causing said valve to open said connection independently of such vacuum condition.

14. InA an automatic clutch-actuating apparatus comprising a vacuum-actuated servo-motor, and a conduit for connecting it to the intake manifold of a motor car, the combination, with said elements, of a valve adapted to completely close all connection between said servo-motor vacuum space and `said intake manifold (when moved in the direction of the iiow of air through said conduit), and so arranged that any suction existing in the manifold tends to hold the valve in such closed position, and means adapted to effect an opening of saidyalve only when the speed changing gears of a car in which said ap` paratus is installed are in a position of low, or intermediate, speed adjustment; whereby, when said gears are in high speed adjustment, said conduit valve is closed and said servo-motor is cut oiT from connection with said manifold, being thereby temporarily rendered inoperative,v and said clutch actuating apparatus is cut out of action.

- HENRY J. Dl N. MCCOLLUM.-

CERTIFICATE oF CORRECTION. Patent No. 2,156,800.. November" l5, 1958.

- HENRY J. DE N. MCCOLLUM. v

It is hereby certified that error appears in the printed specification of the above numbered patent requiring icorrection as follows: Page l, sec- 0nd Column, line 5h. for "eleve" read sleeve; page 2, first column, line 50, strike out the word "is'g line 70, for "isuing" read issuing; page 5, second column, 'line 6, for "closed" read closing; page h, first column, line 2l?, claim 9, for "response" read responsive; and that the said Letters Patenty should be read with this correction therein that the same may conform to, the record of the, case inv the Patent Office. Signed and sealed this 30th day of January, A.. D. l9hO.

Henry Van Arsdale, i (Steal) Acting Commissioner of Patents. 

